Ethacrynic acid
EDECRIN
Pronunciation: eth-a-KRIN-ik AS-id
“Ether cryin’ acid”
Bananas dispersing → ↓ serum potassium
What it isNKCC2-inhibiting loop diuretic; edema when a non-sulfonamide option is required.
Why this oneIts lack of a sulfonamide group is its defining niche among loop diuretics.
What limits itOtotoxicity is greater than with other loops; electrolyte depletion and high cost otherwise mirror the class.
Ethacrynic acid prescription history
Animated chart of estimated U.S. prescriptions per year, Diuretics (1953–2026). Ethacrynic acid enters in 1967 (estimated).
FDA-approved for
- edema (1967)
Principal riskThe highest ototoxicity of the loop diuretics
Sulfonamide
No sulfonamide
The loop diuretic with no sulfonamide group — the traditional alternative after a sulfonamide reaction, though the sulfonamide loops rarely need replacing.
Open the sulfonamide hypersensitivity presentation → · sources [n] are on its References slide.
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityVolume depletion and electrolyte disturbances; kidney function and interacting medications modify risk.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Edema / diuresis | adult | 50 mg QD after a meal | 50-200 mg daily | 200 mg BID |
| Edema / diuresis | pediatric (excl. infants) | 25 mg QD | individualized |
Titration Adjust in 25-50 mg increments; escalate over successive days
Renal Undefined
Hepatic Undefined
Instructions
- Take after meals
- Weigh patient before and during therapy
- Correct electrolyte imbalance; intermittent/alternate-day dosing after dry weight achieved
Available strengths
- tab 25 mg
Contraindications
- Anuria
- Infants
- Severe watery diarrhea from the drug (discontinue, do not rechallenge)
Cautions
- Fluid/electrolyte depletion; dose-related excessive diuresis
- Ototoxicity (deafness, tinnitus, vertigo)
- GI bleeding
- Discontinue in worsening azotemia/oliguria in severe renal disease
Adverse reactions
- GI: anorexia, nausea, vomiting, diarrhea (incl. profuse watery diarrhea)
- Ototoxicity: deafness, tinnitus, vertigo
- Hyperuricemia/acute gout
- Hypoglycemia (excess doses)
- Agranulocytosis/neutropenia, thrombocytopenia
- Headache, fatigue, confusion
Pregnancy No adequate studies; animal studies showed no teratogenicity; use only if clearly needed.
Lactation Undefined
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 25 mg | tab | 30 qd | $24.20 | offered |
Generic entry2016
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Memory aids: interaction avatars
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Self-check
- Which loop diuretic lacks a sulfonamide group?
Ethacrynic acid. - Which toxicity is especially prominent with ethacrynic acid?
Ototoxicity.